java – the loader for Java applications. This tool is an interpreter and can interpret the class files generated by the javac compiler. Now a single launcher is used for both development and deployment. The old deployment launcher, jre, no longer[update] comes with Sun JDK, and instead it has been replaced by this new java loader.

xjc – Part of the Java API for XML Binding (JAXB) API. It accepts an XML schema and generates Java classes.

Experimental tools may not be available in future versions of the JDK.

The JDK also comes with a complete Java Runtime Environment, usually called a private runtime, due to the fact that it is separated from the "regular" JRE and has extra contents. It consists of a Java Virtual Machine and all of the class libraries present in the production environment, as well as additional libraries only useful to developers, such as the internationalization libraries and the IDL libraries.

Copies of the JDK also include a wide selection of example programs demonstrating the use of almost all portions of the Java API.

The JDK forms an extended subset of a software development kit (SDK). It includes "tools for developing, debugging, and monitoring Java applications".[5] Oracle strongly suggests that they now use the term "JDK" to refer to the Java SE Development Kit. The Java EE SDK is available with or without the "JDK", by which they specifically mean the Java SE 7 JDK.[6]

In addition to the most widely used JDK discussed in this article, there are other JDKs commonly available for a variety of platforms, some of which started from the Sun JDK source and some which did not. All of them adhere to the basic Java specifications, but they often differ in explicitly unspecified areas, such as garbage collection, compilation strategies, and optimization techniques. They include: